It is common practice to provide small enclosures or nests for poultry hens to lay their eggs in. Each hen will occupy the nest only for a short period of time during the actual laying of the egg, and when the hen has completed laying the egg, the hen will leave the nest.
Historically it has been common practice to remove the eggs from the nests by hand several times a day. In recent years the eggs have been automatically collected from the nests in various ways. The Rigterrink U.S. Pat. No. 3,164,129 discloses poultry nests from which the eggs will roll by gravity down to a conveyor belt at the rear of the nest for carrying the eggs to a central collecting station. The Peterson U.S. Pat. No. 3,027,871 discloses a swinging panel which pushes the hen off the nest, and then on the backstroke urges the eggs downwardly along the inclined bottom of the nest and onto the collecting shelf.
The Rafaely U.S. Pat. No. 4,188,911 also uses a swinging panel to urge the hen off the nest and has an articulated panel at its lower edge for passing over the eggs as the panel swings in one direction and then ejects the eggs onto a collecting shelf when the panel is swung in the second direction.
It has been determined that as a hen lays an egg, the egg is sterile as it emerges from the oviduct, and has a temperature of about 105.degree. F. As the egg is deposited in the nest, the egg commences cooling and contracting, and because the nesting material in the bottom of the nest contains many contaminants, these contaminants are immediately pulled into the egg and cannot thereafter be removed. It is for this reason that it is desirable to remove the eggs from the nest soon after they are laid so that processing of the eggs may be commenced soon after they are laid.
The most common contaminants include E-Coli, Pseudomonas, Salmonella, and Staphylococcus.